溶剂脱沥青过程的相特性和相平衡研究

溶剂脱沥青过程中的相特性和相平衡试验结果表明，在操作温度低于温溶剂的临界温度下，渣油－溶剂体系一般存在四个相区，即均一液相区、液－液两相区、液－液－气三相区和气－液两相区。 渣油－溶剂体系的性质，组成对各相区的边界有明显的影响，三相区的位置主要由溶剂的种类确定。渣油中掺入一定比例的催化裂化油浆后，扩大了液－液两个相区范围。脱沥青油收率增加，溶剂比增加，脱沥青油收率将增加；压力对脱沥青油收率的影响不容忽视。     

丙烯酸缩水甘油酯的合成工艺改进

采用充分干燥的丙烯酸钠盐为原料和减压抽滤的后处理方法，对传统丙烯酸缩水甘油酯合成工艺进行改进。探讨了丙烯酸钠纯度、含水量、催化剂及阻聚剂品种、反应条件、减压抽滤时蒸馏压力等因素对丙烯酸缩水甘油酯收率的影响。结果表明，当丙烯酸钠纯度99％以上，含水量小于0．5％，十六烷基三甲基溴化铵为催化剂，对苯二酚为阻聚剂，环氧氯丙烷与丙烯酸钠摩尔比为4．5：1，反应温度100～105℃，反应时间2．5h，减压蒸馏压力0．097MPa时，丙烯酸缩水甘油酯收率达92％以上。     

影响油页岩低温干馏因素的考察

对影响油页岩低温干馏的主要因素进行了考察，其中包括最终加热温度、加热时间、加热速度及页岩粒度等因素。结果表明，在最终加热温度500～600℃、加热时间3～4h、加热速度2．5～3．5℃／min、抚顺式干馏炉页岩粒度控制在12～75mm条件下，能提高低温干馏效率。     

常压蒸馏强化剂的研制与工业应用

研究以某炼油厂脱盐、脱水后的原油为原料 ,采用非离子型高分子有机聚合物作活性添加剂 ,强化常压蒸馏过程。介绍了常压蒸馏强化的机理 ,测定了强化剂对轻质油收率及产品质量的影响。实验室及工业应用结果表明 ,在原料油中加入 2 0 0 μg/ g的强化剂 ,可使轻质油收率提高 1.3个百分点以上 ,且产品质量有所改善。     

高硅铝比ZSM-5分子筛的合成及催化裂化性能研究

在实验室以正丁胺为模板剂,在晶化温度160～180℃,晶化时间28～40h,投料硅铝摩尔比100～300的条件下,合成出高硅铝比的ZSM5分子筛,并制备了FCC催化剂。在重油微反装置上对FCC催化剂的评价结果表明,催化剂中HZSM5分子筛硅铝比的提高,可增加轻质油收率及汽油辛烷值,而液化气、干气及焦炭收率减少。     

Influence of Microalloying Elements (Nb,V, Ti) on Yield Strength in Bainitic Steels

In order to study the influence of microalloying elements in bainitic high strength steels, seven steels with different contents of V, Ti, Nb and N were investigated. The steel 35 CrMo 4 (C=0.38; Mn=0.82; Si= 0.25; Cr=0.83; Mo=0.17, all in wt.%) was used as reference steel. CCT diagrams were determined by dilatometric tests at different cooling rates, and the maximum and minimum cooling rates for bainite formation were determined. With regard to tensile tests, the presence of precipitates in the bainitic microstructure contributed to raising their yield strength, as was found by comparing the results for all the steels with the reference steel which did not contain microalloying elements. The yield strength can be predicted by an Orowan expression.     

Airline seat allocation competition

This paper examines the classical seat allocation problem under competition between two airlines with different cost structure. The cost asymmetry that has been ignored in the yield management literature can be caused by either operations or distributions. We investigate the decision problem of two airlines offering two identical fare classes under both the simultaneous and sequential allocations. For both allocation cases, we show the existence, uniqueness and stability of pure‐strategy Nash equilibrium under a reasonable condition on the ratios of relative profit margins of the two fare classes. We find that there will be fewer seats protected for the full‐fare class if the discount seats can be booked first. We found that the asymmetry in costs has two effects on the equilibrium solutions: (a) an airline behaves aggressively for the fare class where it enjoys a cost advantage; (b) an airline tends to balance the trade‐offs internally when it has absolute cost advantage in both fare classes. In deriving the collusive solution for both cases for comparative purposes, we discover new insights by solving the two‐flight, two‐fare seat allocation problem with different cost structures on the two flights. In particular, we show that rivalry in full‐fare seat protection leads to a Prisoners' Dilemma for the carriers. Finally, a numerical example is used to illustrate various analytical results.     

Aromatic DNA adducts in relation to dietary and other lifestyle factors in Spanish adults

The aim of this study was to assess the relationship between bulky DNA adducts in white blood cells (WBC) and lifestyle factors in a sample from the Spanish cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC). 296 subjects aged between 35 and 64 years, from five regions, were included. Food intake was estimated with a computerized version of dietary history questionnaire. Daily intake of polycyclic aromatic hydrocarbons (PAH) was estimated using a database with information on food content of potential carcinogens. Data on lifestyle and health factors were collected and DNA adducts measured using the nuclease P1 ³²P-postlabelling technique. Geometric means of adducts were similar for men and women (4.11/10⁹ and 3.94/10⁹ nucleotides, respectively). Highest levels of adduct were observed in non-smokers and non-occupationally exposed. Meat intake, oils and fats were associated with higher levels of adducts, but all non-statistically significant. Higher intakes of calcium, sodium and phosphorus were associated with lower adducts levels. Summarising, our study shows that bulky adducts measured by ³²P-postlabelling in DNA from WBC do not correlate with the usual diet of healthy Spanish adults. Although it has been proposed that diet be the main source of PAH in nonsmokers without occupational exposure, DNA adducts do not seem to be suitable biomarkers of dietary PAH in general population.     

LC-MS method development to evaluate major triterpenes in skins and cuticular waxes of grape berries

Predominant triterpenes (free oleanolic acid, β-sitosterol and β-sitosterol-3-O-β- d -glucoside) in skin and cuticular wax of grape berries have been analysed by liquid chromatography–mass spectrometry (LC-APCI-MS). The validity of the developed method was established by determining linearity, recovery, precision, accuracy, limit of detection and quantification. Detection limits were in the range of 0.12–0.25 mg L⁻¹, and linearity values ranged up to 105 mg L⁻¹. The repeatability of the method was good. High variability was found among the measured grape varieties based on triterpene content, quantitites of oleanolic acid of cuticular wax ranged from 31.53 mg kg⁻¹ to 162.01 mg kg⁻¹ of the twelve analysed samples. The highest sitosterol content was measured in the sample 'Othello' (73.12 mg kg⁻¹), while maximum sitosterol glucoside content was also found in 'Othello' variety (13.68 mg kg⁻¹). The results showed that the study on triterpenes could be an informative tool to characterise grape varieties.     

Genetic parameters for carcass composition and performance data in crossbred lambs measured by Video Image Analysis

A total of 7074 crossbred lambs, produced by mating crossbred Mule ewes with terminal sire rams were used in this study. Of these, 630 were scanned using a Video Image Analysis (VIA) to estimate carcass quality traits. Genetic parameters for average daily gain (ADG), scanning live weight (SW), ultrasonic measures of muscle (UMD) and fat (UFD) depths, cold carcass weight (CCW) and VIA measurements of primal carcass joint weights (LEG, CHUMP, LOIN, BREAST and SHOULDER) were estimated using multivariate animal models. Additionally, VIA traits were evaluated under a repeatability model, considering the primal joints as repeated measures of the same trait. Direct heritability estimates were low to moderate (0.08–0.26) for VIA measurements of primal joints. Repeatability estimates for VIA traits were high (>0.90). Moderate to high heritability estimates (0.25–0.55) were found for performance traits (ADG, SW, UMD and UFD) and CCW. Genetic correlations between VIA traits and ADG were strong (0.75–0.93). Most of the VIA traits were highly correlated to SW (0.60–0.97). UFD was significantly negatively correlated with UMD (−0.22), ADG (−0.18) and CCW (−0.18). The results of this study suggest that selection on performance and carcass traits, measured by VIA, could possibly improve primal meat yield of carcass cuts without increasing the overall carcass fatness. High repeatability estimates of VIA traits and moderate heritabilities of the most valuable carcass joints suggests that including VIA information in breeding programs would be useful in order to improve carcass quality.